A Method to Screen Anticholesterol Substances produced by Microbes and a New Cholesterol Oxidase produced by Streptomyces violascens

A new method to screen anticholesterol substances produced by microbes was devised and the method was applied for cultured broth of Streptomyces. Only one strain, resembled to be Streptomyces violascens, out of more than 200 Streptomyces was determined to produce an anticholesterol substance by this screening method. Furthermore, a new method to measure the anticholesterol activity was established for fermentation and purification of the active component. The partially purified active component was proved to be a new enzyme which oxidized cholesterol to cholest-4-en-3-one. Nicotinamide adenine dinucleotide or nicotinamide adenine dinucleotide phosphate was not necessary for this enzymatic oxidation. It was found that the enzyme was active against the 3β-hydroxyl group on the steroid skeleton but not against the 3α-hydroxyl group by investigating the substrate specificity of the enzyme.